The present invention relates to a processed dehydrated brassica vegetable composition and a method of its manufacture.
Broccoli and other brassica vegetables may be helpful in fighting cancer and other diseases. These vegetables contain glucosinolates such as glucoraphanin that can be converted into biologically useful isothiocyanates. These vegetables also contain endogenous myrosinase enzyme, which converts glucosinolates into isothiocyanates such as sulforaphane. Isothiocyanates, especially sulforaphane, can help the body fight disease by inducing phase II enzymes that are present in the human body and that are capable of detoxifying carcinogens. For this reason, broccoli and other brassica vegetables are often included in dietary and nutritional supplements.
U.S. Pat. No. 5,882,646 (the ""646 patent) discloses a dietary supplement containing a brassica vegetable and an exogenous source of myrosinase enzyme. The supplement of the ""646 patent contains pre-formed isothiocyanates such as sulforaphane rather than glucosinolates. Unfortunately, pre-formed isothiocyanates are not stable compounds. Isothiocyanates can degrade over time, thereby losing their beneficial biological activity.
Also, the process of making the dietary supplement of the ""646 patent inactivates the endogenous myrosinase enzymes in the brassica vegetables. Unfortunately, the inactivation of the endogenous myrosinase in the ""646 patent requires the addition of exogenous myrosinase enzyme, and therefore does not capitalize on the naturally-occurring endogenous myrosinase in the processed vegetable.
Accordingly, a composition is needed that contains stable glucosinolates rather than unstable, pre-formed isothiocyanates. The stable glucosinolates are converted into biologically useful isothiocyanates upon ingestion. This way, the isothiocyanates are not given an opportunity to degrade before they are ingested. Also, a process of making a brassica vegetable composition is needed that retains the activity of the endogenous myrosinase enzyme during processing while preventing the endogenous myrosinase enzyme from prematurely converting a substantial amount of the glucosinolates into unstable isothiocyanates.
The compositions and methods of this invention solve at least some of the problems of the prior art. Specifically, in the present invention, brassica vegetables are processed such that the natural myrosinase enzyme endogenous to the brassica vegetables remains intact throughout the processing. The composition produced by the process contains glucosinolates and active endogenous myrosinase enzyme. Then, when the composition is ingested by a human (or introduced into another aqueous environment), the endogenous myrosinase enzyme converts the glucosinolates into biologically useful isothiocyanates.
As used herein, xe2x80x9cendogenous myrosinase enzymexe2x80x9d refers to myrosinase enzyme that is produced from within a particular brassica vegetable. xe2x80x9cExogenous myrosinase enzymexe2x80x9d refers to myrosinase enzyme that is introduced to a particular brassica vegetable from outside of that vegetable. For example, myrosinase enzyme that is endogenous to horseradish root is exogenous with respect to broccoli.
In one aspect of the invention, a composition comprises at least one processed dehydrated brassica vegetable containing glucosinolates and endogenous myrosinase enzyme, wherein the endogenous myrosinase enzyme converts the glucosinolates into isothiocyanates when the composition is ingested.
In another aspect of the invention, a method of making a processed dehydrated brassica vegetable composition is provided. The method comprises (a) chopping at least one brassica vegetable in such a way that the myrosinase endogenous to the brassica vegetable converts only an insubstantial amount of glucosinolates into isothiocyanates; (b) blanching the at least one brassica vegetable in such a way that the activity of the endogenous myrosinase enzyme is preserved; (c) dehydrating the at least one brassica vegetable in such a way that the activity of the endogenous myrosinase enzyme is preserved; and (d) grinding the at least one brassica vegetable into a powder such that, when the powder is ingested, the endogenous myrosinase enzyme converts the glucosinolates into isothiocyanates.
The above and other aspects and advantages of the present invention will become apparent from the following figures and the detailed description of the preferred embodiments. Note that all percentages referred to in this document are weight percentages unless otherwise indicated.